A Study on Crystallization Process and Rheological Properties of Polypropylene in Addition of Polysilane

Abstract

The crystallization behavior and rheological properties of PP in addition of polysilane which consists of Si-Si conjugation as a main chain were investigated. From the DSC measurement results, it was found that the crystallization temperature, melting point, and equilibrium melting point of PP decreased monotonically as the amount of PMPS added increased. On the SAXS measurement, the addition of PMPS reduces the long period and lamella thickness of PP crystals, while increasing the amorphous phase thickness and reducing the surface free energy. In the crystallization process, the temperature profile of the relative crystallization degree was shifted to the long-term side by adding PMPS to PP, and the crystallization was delayed. As a result of analyzing the compatibility between PP and PMPS with reference to the method of Nishi-Wang, it was deduced that these materials were compatible. From rheological measurements, it was found that PP in the molten state induces a decrease in viscosity due to the addition of PMPS, and the temperature dependence of the change also increased. Regarding the molecular motion in the solid state, it was found that the segment motion of PP near Tg was improved by the addition of PMPS. Finally, the uniaxial tensile test showed that the PP elastic modulus and yield stress decreased, but the elongation at break improved significantly.